To save all images of a page, there is a similar
action already present in K-Meleon :

Go to
View/Images to open all page images on one page,
right click on this page, and save this page
as Webpage-Complete to a location of your choice.
This will save all images at the same time
into a folder.

You can unpack the .xpi after renaming it to .zip
and put the parts to the place where they belong
in K-Meleon (chrome, defaults/prefs) and write a
.kmm macro to call the xul up in the browser.
The extensions converter made by disrupted may
be a help :
http://kmeleon.sourceforge.net/forum/read.php?1,89855
If the extension refers to and needs parts from
Firefox chrome it would not work.
You could try to add the missed parts, or would
have to alter the extension scripts, which would
ask for considerable scripting knowledge and is not
easy.
Many extensions would never work because of the
different browser structure.
Some more posts about adding extensions here :
http://kmeleon.sourceforge.net/forum/read.php?1,73114
and in many other threads, that you can find using
Google, if the Forum search should still not work
as it should. Write the keywords and add
site:kmeleon.sourceforge.net
to the Google search string.